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Updated: Mar 30, 2026
07:46
Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
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Lepton flavour violating top decays at the LHC.
Sacha Davidson1, Michelangelo L Mangano2, Stéphane Perries1
1IPNL, CNRS/IN2P3, 4 rue E. Fermi, 69622 Villeurbanne Cedex, France ; Université Lyon 1, Villeurbanne, France ; Université de Lyon, 69622 Lyon, France.
The European Physical Journal. C, Particles and Fields
|November 7, 2015
Summary
Top quarks may undergo lepton-flavour violating decays through 4-fermion operators. Current LHC data can probe these decays, with future data offering enhanced sensitivity to rare top quark processes.
Area of Science:
- High Energy Physics
- Particle Physics
- Quantum Field Theory
Background:
- Top quark decays are crucial for understanding the Standard Model.
- Lepton flavour violation (LFV) is a key indicator of new physics beyond the Standard Model.
- Four-fermion operators can mediate LFV processes involving the top quark.
Purpose of the Study:
- To investigate and constrain lepton-flavour violating (LFV) decays of the top quark.
- To analyze the impact of SU(3) x U(1)-invariant 4-fermion operators on top quark decays.
- To determine the sensitivity of current and future Large Hadron Collider (LHC) data to these LFV decays.
Main Methods:
- Compilation of constraints on a complete set of SU(3) x U(1)-invariant operators.
- Analysis of loop contributions to rare decays.
- Inclusion of constraints from HERA's single-top search.
- Estimation of sensitivity reach using LHC data at 8 TeV and extrapolation to 13 TeV.
Main Results:
- Bounds on electron-tau flavour change are more restrictive than on electron-muon flavour change.
- The top quark could decay to a jet with a branching ratio of order 10^-3.
- Current LHC data (20 fb^-1 at 8 TeV) is sensitive to top quark decays to electron + jet.
- Extrapolation suggests 100 fb^-1 at 13 TeV could reach a sensitivity of 10^-4.
Conclusions:
- LFV decays of the top quark are constrained by existing experimental data.
- The top quark remains a viable channel for discovering new physics through LFV.
- Future LHC data will significantly improve sensitivity to these rare top quark decay modes.
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